1. Field of the Invention
The present invention relates to medical equipment for helping a patient to breathe in a medical field, more specifically, to an improvement of a medical instrument, referred to as a so-called “airway”, which improves a state of falling of a tongue root of a patient to maintain an air passage in a pharynx portion.
2. Description of the Related Art
In a normal case, one can breathe easily even when one is lying on one's back because an air passage in a pharynx portion is maintained to allow an air to pass behind a tongue root (see FIG. 7(a)). In a case of a consciousness disorder, however, one will fall into a state of difficulty in breathing when one is lying on one's back because the tension of a muscle is lost so that a tongue root may fall into and block a passage, through which air passes, that is, an air passage in a pharynx portion (see FIG. 7(b)). This necessarily allows the condition of the patient to take a turn for the worse.
In such a case, it is required in one way or another to provide a passage necessary for breathing (to maintain an air passage) to allow a patient to be able to breathe easily. In this case, a medical instrument 51, referred to as a so-called “airway”, as shown in FIG. 6, is generally used, the medical instrument 51 comprising an umbrella-shaped stopping portion 54 for handling which will be exposed to the outside of a mouth, a linear introducing portion 53 which transits from the umbrella-shaped stopping portion 54 to a portion for an oral cavity, and a curve-shaped oral cavity inserting portion 52 which is continued to the linear introducing portion 53, the medical instrument 51 being of approximately H-shaped cross section, and having concave recessing portions 55 and 55, which define spaces for breathing on both sides of the instrument 51, wherein the medical instrument 51 can be inserted from a mouth into a pharynx portion to elevate a tongue root portion A to maintain an air passage in the pharynx portion (see FIG. 7(c)).
However, the above-mentioned medical instrument does not always match the shape of a tongue, which sometimes may lead to a constrained state. Although a tongue which comprises a mass of sarcous can be deformed according to conditions, its entire profile can have a natural curve without strained convex or concave. However, following a portion transiting from the portion for an outside of a mouth to the portion for an oral cavity, the above-described medical instrument bends at a steep angle not only at the portion transiting from the linear introducing portion to the curve-shaped oral cavity inserting portion, but also is curved at a steep angle at the curve-shaped oral cavity inserting portion. As a result, the bending portion and the curved portion of the medical instrument tend to press a tongue in a direction to a tongue root.
In addition, the above-mentioned medical instrument is difficult to insert into a pharynx portion. That is, the instrument has the demerit of being very hard to manipulate because the instrument has a specifically fixed shape as noted above, so that the bending portion and/or the curved portion thereof may often hit against a portion, such as a lip, an incisor, or a palate and so on during the insertion.
Further, it is difficult to aspirate phlegm when using the above-mentioned medical instrument. That is, since a tube for aspiration is inserted through either one of the concave recessing portions on both sides of the instrument with approximately H-shaped cross section and the instrument has a specifically fixed shape as stated above, the tube for aspiration may be caught on the bending portion and/or the curving portion and cannot go into further.
Furthermore, a tongue root is not sufficiently elevated when using the above-mentioned medical instrument. Since the object of the instrument of this type is to maintain an air passage in a pharynx portion by inserting the instrument of the above-described specific fixed shape between a tongue and a palate, a space for an air passage obtained is limited by the size of the cross section of the instrument. If the cross sectional area of the instrument is provided to be large enough to elevate a tongue sufficiently, another inconvenience occurs instead, that is, it becomes more difficult to insert the instrument due to its specific shape.
Additionally, the above-mentioned medical instrument after using is not easy to clean. Considering problems of hygiene and disinfection of medical instruments from the viewpoint of bacterial proliferation, when proteins remain on the surface of an instrument, an effect of a disinfectant will decrease greatly thereby allowing bacteria to proliferate easily. The above-stated instrument has many concave recessing portions which are not easy to clean due to the approximately H-shaped of the cross section as stated above.